After too long of an absence, Probably History returns with a lively discussion of Pompeii and the eruption of Mt. Vesuvius. Comedian Mark Agee (twitter.com/markagee) joins Jesse Case, Andy Wood and Richard Bain to talk about life in first-century Rome, pyroclastic flows and the importance of knowing when to evacuate.

Comedy writer Michael James Nelson (michaeljamesnelson.com) has worked on Betty White's Off Their Rockers and many other shows in spite of the fact that as a young man he was convinced he would pursue a career in science and work on the Space Shuttle. He joins Matt, Andy and return guest Robert Buscemi this week to talk about: Magnet schools: How do they work? Growing up with multiple learning disabilities! The varying definitions of nerd-dom! The awesomeness of Betty White! Nice pranks! Last week's asteroid close-call! Fox News and their assessment of the value of space water! Drilling into the surface of Mars! Space cats! Using color patterns to search for extraterrestrial life! The bones of Richard III! The uncertainty principle demonstrated on a (somewhat) grand scale! Literal pecking orders! How to get alpha eggs at your local grocery store!

David Huntsberger (twitter.com/huntsbergerjunk) from Professor Blastoff (professorblastoff.com), a podcast that Probably Science in no way plagiarizes, joins Matt and Andy this week to discuss: Getting deputized to substitute teach under Texas educational martial law! Narrowly avoiding dating minors! Trash-talking Bear Grylls! Ill-fitting letter jackets! High school rodeo teams! The redundancy of assless chaps! Team roping! A monkey midwife! Are there more types of otters than bears? The importance of giant prime numbers! The loneliness of Google Street View team members! The uselessness of Yelp reviews! The unintentional upside of oceanic pollution!

Dr. Peter McGraw (twitter.com/petermcgraw) heads the Humor Research Lab (HuRL) at UC Boulder, and he joins Matt, Andy and returning guest Baron Vaughn (twitter.com/barvonblaq) for a special episode devoted entirely to the science of why things are funny. Peter's Benign Violation Theory is a robust, empirically testable explanation of humor in all its forms, and it's the basis of Peter and Joel Warner's upcoming book The Humor Code. For more information on Peter's work, visit humorcode.com and humorresearchlab.org.